New comment by tornaria on void-packages repository

https://github.com/void-linux/void-packages/pull/32822#issuecomment-912837688

Comment:
More on singular:
 - can you enable readline for the command line?
 - we need to figure out if/how to split singular in pkgs: what's the minimum needed to run the command line?
 - it seems ntl is not being picked up; need to add ntl-devel to makedepends
 - python executable is searched in configure: I don't know what for.
 - dot seems to be needed to build graphics for the documentation (dot is in `graphviz` but cf #32826).